05-03-2013
Bash Lockfile Command
Hi,
I am new to this forum, could any one please help me to understand the LOCKFILE command with an example and what exactly it is used for and how it is used.
Thanks
Reshu289
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
In my script I use this command \c when printing(echo) out statements but this only works in the Korn Shell(ksh).
I need the same command to be used in the Bash Shell, is there one out there?
Thanks,
the A. (1 Reply)
Discussion started by: Astudent
1 Replies
2. Shell Programming and Scripting
Hi,
I have written below check lockfile script but need some tweaking on it.
If there is a lockfile from present, I need the script to retry every 10 seconds to see if the lockfile is still there. After 120 seconds it should send an email.
In my current version, if the script encounters... (6 Replies)
Discussion started by: Meert
6 Replies
3. Shell Programming and Scripting
Just tried out the following code from "Using lockfiles in shell scripts":
#!/bin/bash
if ; then
echo "File exists"
else
echo "File does not exists. Create file now."
echo 1 > number.txt
fi
lockfile script.lock
a=$(/usr/bin/tail -n 1 number.txt)
if ; then... (1 Reply)
Discussion started by: courteous
1 Replies
4. AIX
Server: IBM p770
OS: AIX 6.1 TL5 SP1
When one of our develoeprs types "bash" on the command line to switch shells, it hangs. For some reason, two bash processes are created....the first bash process spawns a second bash process in the same console, causing a hang. Anyone have any idea what... (2 Replies)
Discussion started by: wjssj
2 Replies
5. UNIX for Dummies Questions & Answers
I'm reading about debugging aids in bash and have come across the set command. It says in my little book that an addition to typing
set
you can also use them "on the command line when running a script..." and it lists this in a small table:
set -o option Command Line... (5 Replies)
Discussion started by: Straitsfan
5 Replies
6. UNIX for Advanced & Expert Users
Hi all,
I have to test some user priviliges. The goal is to be sure that an unauthorized user can't restart some modules (ssh, mysql etc...).
I'm trying to automate it with a shell script but in same cases I got the syslog broadcast message.
Is there any way to simply get a return code... (3 Replies)
Discussion started by: Dedalus
3 Replies
7. Shell Programming and Scripting
I created a script that I need to run from time to time, but get this error message. To get it working again I run this command from time to time:
export PATH="$PATH:~/scripts"
I put all my automated scripts in the /scripts directory and would like to run my scripts from any directory... (5 Replies)
Discussion started by: catalinawinemxr
5 Replies
8. UNIX for Advanced & Expert Users
Hi,
I have a process which can run one instance at a time. Currently we have multiple scripts trying to kickoff this process. I wanted to implement the semaphore mechanism to achieve this.
I was going through few examples. The below code seems to be reasonable solution.
... (5 Replies)
Discussion started by: tostay2003
5 Replies
9. Shell Programming and Scripting
The below command moves all the .vcf files into the directory.
cp /home/cmccabe/Desktop/test/vcf/overall/stats/*.vcf /home/cmccabe/Desktop/NGS/annovar
When I use a bash wrapper the target.txt gets created but the text files do not get copied. All the paths are the same, but not sure why... (2 Replies)
Discussion started by: cmccabe
2 Replies
10. Shell Programming and Scripting
How to run several bash commands put in bash command line without needing and requiring a script file.
Because I'm actually a windows guy and new here so for illustration is sort of :
$ bash "echo ${PATH} & echo have a nice day!"
will do output, for example:... (4 Replies)
Discussion started by: abdulbadii
4 Replies
LEARN ABOUT DEBIAN
paranoid::lockfile
Paranoid::Lockfile(3pm) User Contributed Perl Documentation Paranoid::Lockfile(3pm)
NAME
Paranoid::Lockfile - Paranoid Lockfile support
VERSION
$Id: Lockfile.pm,v 0.65 2011/12/08 07:53:07 acorliss Exp $
SYNOPSIS
use Paranoid::Lockfile;
$rv = plock($lockfile);
$rv = punlock($lockfile);
$rv = pcloseLockfile($lockfile);
DESCRIPTION
This modules provides a relatively safe locking mechanism across multiple processes. This does not work over NFS or across remote systems,
this is only intended for use on a single system at a time, and only on those that support flock.
sysopen is used to avoid race conditions with multiple process attempting to create the same file simultaneously.
SUBROUTINES
/METHODS
plock
$rv = plock($filename);
This function attempts to safely create or open the lockfile. It uses sysopen with O_CREAT | O_EXCL to avoid race conditions with other
processes. Returns a true if successful.
Your can pass an optional second argument which would be a string of either 'write' or 'shared'. The default is 'write', which locks the
file in exclusive write mode.
You can pass an optional third argument which would be the lockfile filesystem permissions if the file is created. The default is 0600.
NOTE: This function will block until the advisory lock is granted.
punlock
$rv = punlock($filename);
This function removes any existing locks on the specified filename using flock. If no previous lock existed or it was successful it
returns true. This does not, however, close the open filehandle to the lockfile.
pcloseLockfile
$rv = pcloseLockfile($filename);
This function releases any existing locks and closes the open filehandle to the lockfile. Returns true if the file isn't currently open or
the operation succeeds.
DEPENDENCIES
o Fcntl
o Paranoid
o Paranoid::Debug
BUGS AND LIMITATIONS
AUTHOR
Arthur Corliss (corliss@digitalmages.com)
LICENSE AND COPYRIGHT
This software is licensed under the same terms as Perl, itself. Please see http://dev.perl.org/licenses/ for more information.
(c) 2005, Arthur Corliss (corliss@digitalmages.com)
perl v5.14.2 2011-12-08 Paranoid::Lockfile(3pm)